The present invention relates to sketching and measuring tools, rulers, protractors, devices for creating geometric shapes, and combinations thereof.
Many mechanical devices have been proposed and/or used for measuring and sketching straight lines, angles, and combinations of the same. The most common of these are straight rulers, stacked rulers with a fixed pivot, t-squares, adjustable t-squares, protractors, protractors with indicating arms, triangle rulers, squares rulers, adjustable fixed-length triangles with limited angle variability, and fixed-angle devices, such as scalable squares and frames.
However, most, if not all of these devices have limited intended uses: e.g., typical standalone rulers and T-squares are only useful in sketching and measuring straight lines; standalone protractors typically only allow for angle measurement and do not facilitate sketching; stacked rulers with a fixed pivot only allow for angle creation where at the location on the ruler where the fixed pivot point is located; fixed-length and variable-angle triangular sketch and measure devices can only be used over a small range of angles; scalable squares and frames have fixed angles and thus, are not useful for creating and scaling other shapes, etc.
More recently, combinations of rulers and protractors have appeared in the art, but these devices have limited intended uses, too. An example is the stacked, two-ruler configuration (U.S. Pat. No. 7,082,692 B2) with a sliding pivot element that fastens the two rulers of this assembly together and that is centralized in a slot that is common to the each of the stacked rulers; this configuration allows for an angle to be created at any metric point along the edge of each ruler where the rulers' edges intersect each other. However, if an angle is created at a certain metric, e.g., the 5 inch mark, and the angle is subsequently changed, this change causes the point of intersection (vertex of the angle) between the two rulers to move along the metered edges of each ruler; i.e., the vertex of the angle moves away from the 5 inch mark.
A second issue with this type of design is that the two rulers with the pivot element are fixed to each other either permanently or semi-permanently, and these modes of attachment do facilitate rapid interchangeability between rulers (no quick connect/disconnect mechanism) or the addition of multiple rulers to create a super-assembly and thus, multi-sided shapes. Third, this stacked configuration causes each ruler to be raised off the sketching or measuring surface by a different height, which makes sketching and measuring along a stacked ruler's edge both inaccurate and difficult.
Perhaps, the most versatile of these devices that appears in the art is a ruler system composed of a central protractor piece that is permanently fastened to two rulers both of which emanate from the central protractor piece (U.S. Pat. No. 5,732,474). In this design, rulers act as legs and are allowed to rotate independently of each other: one ruler is hollow and acts as a sleeve; the other ruler is solid and acts as a male mating piece. This configuration allows for the male leg or insert of a second, same device to be inserted into the female leg or sleeve of a first device, and vice versa, thereby allowing for numerous shapes and mating configurations to be formed.
However, like the aforementioned devices, this device, too, has design issues that limit its intended uses. First, the length of the longest leg, regardless of whether the longest leg is the male or female mating member, is minimum separation distance that can be achieved between protractors when the male leg from one device is inserted into a female leg of another device. Second, the largest separation achievable between protractors must be less than the sum of the male and female legs added linearly, since the male leg must have, at least, some small amount of material inserted into the female leg in order to hold the configuration of parts together. Both of these facts attest to the limited scalability of this design. Third, the sleeve design itself creates a width-wise step along the edges of the mated rulers, which obscures both the sketching and measuring of straight lines. Further, this same mating design also creates an issue of overlapping ruler markings, where the marking on the male leg (insert) become either hidden or obscured by the markings on the female leg (sleeve), depending or a whether an opaque or transparent material, respectively, is used to construct these devices. Additionally, it is inevitable that the marking on the female and male legs must move past each other in opposite directions, regardless of the desired configuration; this creates a confusing situation when one attempts to make a linear measurement with any mated portions of a multi-device assembly of this type, since there is no significant meaning between distance of the measurement marking on oppositely moving and mated legs of different devices. As claimed in (U.S. Pat. No. 5,732,474), this device was only intended to be a visual aid, and it is mostly because of the said limitations.
Accordingly, there is a need for a design that resolves the deficiencies in the aforesaid devices and one that introduces a set capabilities not yet seen in the prior art.